International Journal of Marine Science 2015, Vol.5, No.52: 1-8
1
Research Report Open Access
n
-Alkanes in surficial soils of Basrah city, Southern Iraq
Al-Saad H.T.
1,
, Farid WA.
2
, Ateek A.A.
3
, Sultan A.W. A.
3
,Ghani,A.A,
1
Mahdi S.
1
1. Dept. Of Marine Environmental Chemistry- Marine Science Center, University of Basrah, Iraq
2. College of Health and Medical Technology, Southern Technical University, Basrah, Iraq
3. Technical College, Southern Technical University, Basrah, Iraq
Corresponding author email
International Journal of Marine Science, 2015, Vol.5, No.52 doi
Received: 06 Jul., 2015
Accepted: 07 Aug, 2015
Published: 31 Aug., 2015
Copyright
©
2015 Al-Saad et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article: Al-Saad H.T., Farid W A., Atik A.A., Sultan A.W. A,Ghani,A.A,and Mahdi S., 2015,
n-
Alkanes in surficial soils of Basrah city,
Southern Iraq, International Journal of Marine Science, 5(52): 1-8
Abstract
A study has been carried out to determine the distribution of aliphatic hydrocarbons in surface soils of Basrah city,
southern Iraq. One hundred twenty eight surface soil samples (0-10 cm depth) were collected from sixteen sites around Basrah city
covering commercial ports, industrial and oil operational locations, urban and rural areas. Hydrocarbons were extracted with mixture
of benzene: methanol using soxhlet technique and fractioned with silica-alumina column. Characterization of individual hydrocarbon
components was carried out using gas chromatography-flame ionization detector. Average of the total identified
n
-alkanes
concentrations in soil samples were found ranging from 03.575 to 21.266 µg g
-1
dry weight. Carbon Preference Index (CPI) values
for
n
-alkanes varied between 0.893 and 5.57. The isoprenoids, pristane and phytane were detected in most soil samples. Unresolved
Complex Mixture (UCM) values ranged from 5.2 to 12.3 µg g
-1
dry weight. No significant correlation between soil , % Total Organic
Carbon (% TOC) and the concentrations of
n
-alkanes was observed. Results indicated that the aliphatic hydrocarbons were from both
biogenic and anthropogenic sources. Generally, the results show that the total
n
-alkanes concentrations were higher in winter and
autumn than that recorded for spring and summer.
Keywords
Soil pollution;
n
-alkanes; Gas Chromatography; Basrah city
Introduction
Soil contamination by hydrocarbons is an important
problem in many areas of the oil-producing countries.
Hydrocarbons can contaminate soil through many
sources that include leakage of storage tanks and
pipelines, land disposal of petroleum wastes and
accidental spills
(Barakat
et al., 2001; Kèlomèet al.,
2012). Although most of the hydrocarbons present in
the soil resulting from anthropogenic activities. Soil
contains relatively small amounts of natural hydrocarbons
(biogenic) such as those synthesized by certain
organisms (e.g. higher plants and microorganisms)
(Zhang et al., 2012). The hydrocarbons in soil are
strongly related to the sorbet organic matter and this
depended on the nature of the hydrocarbon and the
organic matter content (Sadler and Connell, 2003).
However, the hydrocarbons can be removed from the
soil by different processes such as volatilization,
reaction, leaching and biodegradation. Some of these
processes take a long time to remove hydrocarbons
from the soil depending on the environmental conditions,
so the part of these compounds will remain steady in
the soil and become more resistant (Kèlomèet al.,
2012; Olubunmi
et al., 2012). The increase in the
concentrations of hydrocarbons in the soil may cause
adverse effects on the ecosystem, and some hydrocarbons
are considered carcinogenic and mutagenic where
they can cause serious health problems for humans
and other living resources
(Iturbe et al., 2004; Teaf et
al., 2008).
Basrah, a city located in southern Iraq be rich in oil.
Many oil operations had achieved in this city after
2003 by many international oil companies, So high
concentrations of hydrocarbons expects their presence
in its soil. In addition to the oil operations there are
other sources of petroleum hydrocarbons may also
contaminate the soil of this region include industrial
factories, electric power stations and gas production
plants. However, there are few studies estimated the
levels of petroleum hydrocarbons in this city (Douabul
et al., 2012), which must have precedence from the
environmental point of view. Thus, the present study
was carried out to determine the distribution and
seasonal variations of petroleum hydrocarbons in
sixteen sites in Basrah governorate. The results obtained in
